Fireproof furniture



SMEs, a@ K Lim@ @5U-m @fin-:ESI @rafsmm E. T. HOLMBERG.

EIREPHOOF FURNITURE.

APPLICATION FILED Nov.2s, 1920.

1,4: 1 2,784. Patented Apr. '11, 1922.

UNITED STATES Dra ffsman PATENT OFFICE.

EDGAR T. HOLMBERG, 0F CLEVELAND, OHIO, ASSIGNOR T0 THE JAMES lH2. HERRON COMPANY, OF CLEVELAND, OHIO, A CORPORATION 0F OHIO.

FIREPROOF FURNITURE.

Specification of Letters Patent.

Patented Apr. 11, 1922.

To all whom t may concern.:

Be it known that I, EDGAR T. IIoLMBERG, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Fireproof Furniture, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to fireproof furniture such as safes, filing cabinets, strong boxes and similar articles, and has for its objects, to provide an article of the aforementioned class which shall be particularly effective in resisting excessive heat; to provide an insulating layer for such articles which can be readily applied and which, when finished, shall be proof against disintegration at any conflagration temperature and shall have a coefficient of expansion sufficiently small to avoid cracking and suf* ficiently near that of steel to avoid breakdown; while further objects and advantages will appear as the description proceeds.

In the accompanying drawing, the figure represents a safe rendered fireproof in accordance with my invention.

Describing by reference characters the various parts illustrated, 1 indicates a suitable metal casing which surrounds and is spaced apart from the side walls 2, the rear wall 3 and the bottom of said safe, these parts being preferably of thin steel. The side and rear walls of the casing 1 are preferably extended above the inner walls of the safe as indicated at 4, a distance substantially equal to the distance between the inner walls and the casing 1. The intervening space between the inner walls of the safe and casing 1, is filled with my fireproof material 5 which is preferably of such nature that it can be mixed in a liquid form and poured about the safe and afterward will harden into a solid, although I do not restrict myself to this mode of application. My improved insulating composition consists of substantially equal parts of corn size kieselguhr which has been previously calcined to a temperature between about one thousand degrees and two thousand degrees C., and a binder such as plaster of Paris. After mixing the dry ingredients thoroughly together I then add sufficient water to obtain the desired plasticity for pouring. This liquid mass is then poured into the space between the walls of the safe and the metal lining 1 in sufficient quantity to fill said space and also to cover the top of the safe to a depth level with the extended portions of the casing 1. The door 6 is also provided with a spaced casing 7 and the space therebetween is filled with the aforesaid fireproof material.

After the insulating material has been poured as aforesaid, it is allowed to stand for a time to evaporate the excess of free water remaining after the setting of the plaster of Paris, after which the article is preferably placed in a drying oven and heated to 212 F. for a suitable period to drive out the remaining uncombined moisture. After this the top cover plate 8 is set in place and fastened, in case this be the construction employed.

I thus provide a fireproof casing about the safe which is devoid of all joints except where the door 5 is positioned, and hence reduces to a minimum the possibility of heat expanding the material and opening up seams thus leading to a destruction of the contents of the safe. When such an article is exposed to confiagration conditions the metallic shell is frequently burned completely away without any such spalling or cracking of the insulating composition as to permit any injury whatever to papers or jewelry inside the same. I have found that by using equal parts by weight of calcined kieselguhr and plaster of Paris I obtain a compound which will withstand very high temperature without cracking, shrinking or decomposing, and which is light in weight and hence exceedingly desirable for use in fireproofing safes or other furniture. If used on articles where shrinkage is not objectionable, I may increase the amount of kieselguhr, or if weight and slight cracking is not objectionable I may increase the amount of plaster of Paris.

My compound is particularly adapted for fireproofing metallic articles as there is no chemical action between the ingredients and it contains no ingredients which attack metal. It is able to withstand high temperatures in the neighborhood of 2000o F. without decomposition as it contains no ingredients such as asbestos or organic compounds which decompose at or below such temperature. The preferred composition produces a ireproof substance which when dry, is hard and firm and not `easily cracked or broken by handling.

Having thus described my invention, What I claim is:

l. An article of ireproof furniture including an insulating layer of fireproof material which is devoid of all joints except Where access is gained to the interior thereof7 said material being composed essentially of calcined kieselguhr and plaster of Paris.

2. An article of fireproof furniture having a chambered Wall lled with a ireproof material composed of equal parts of calcined liieselguhr and plaster of Paris.

3. An article of fireproof furniture hav ing a Wall made of tWo spaced metal plates defining a chamber Which is filled With a mixture of substantially equal parts ofv plaster of Paris and corn size calcined kieselguhr.

4. The process of making a composite fireproof article Which .contains the steps of calcining corn size kieselguhr to a temperature between about 10000 and 2000o C.,

mixing the same with substantially an equal Weight of dry powdered plaster of Paris,

EDGAR T. HOLMBERG. 

